This invention concerns an oil seal for sealing off a fast rotating shaft relative to a housing and including a first seal element associated with and corotating with the shaft, a second seal element associated with the housing, annular contact surfaces on the seal elements, and a spring means exerting an axial bias force on one of the seal elements so as to provide a contact pressure between the contact surfaces.
A problem concerned with oil seals of the above type is that there are extremely high demands on the accuracy of the contact surfaces to obtain a perfect tightness. To satisfy these demands there is required a costly and space demanding seal design. This is a serious drawback when employing this type of seal on a small size machinery where both costs and space are important to minimize.